Related Experiment Video
Updated: Jun 12, 2026
08:03
Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes
Published on: June 25, 2017
Long-term hyperglycaemia decreases gastrocnemius susceptibility to permeability transition
José Lumini-Oliveira1, António Ascensão, Cláudia V Pereira
1Research Centre in Physical Activity, Health and Leisure, Faculty of Sport Sciences, University of Porto, Porto, Portugal.
European Journal of Clinical Investigation
|May 22, 2010
Summary
Long-term hyperglycemia in rats reduced gastrocnemius mitochondrial respiratory control and calcium-dependent mitochondrial permeability transition pore (MPTP) opening. This suggests organ-specific mitochondrial effects of high blood sugar.
Area of Science:
- Mitochondrial physiology
- Diabetic complications
- Skeletal muscle biology
Background:
- Hyperglycemia is linked to skeletal muscle dysfunction via mitochondrial complications.
- Investigating long-term hyperglycemia's impact on gastrocnemius mitochondria is crucial.
Purpose of the Study:
- To analyze the effect of long-term severe hyperglycemia on gastrocnemius mitochondrial bioenergetics.
- To determine the susceptibility to mitochondrial permeability transition pore (MPTP) opening under hyperglycemic conditions.
Main Methods:
- Adult male Wistar rats were divided into control and diabetic groups (n=8).
- Diabetes was induced via streptozotocin (STZ) injection.
- Mitochondrial function, MPTP induction, and caspase 9 activity were assessed after 18 weeks.
Main Results:
- STZ treatment decreased respiratory control ratio with complex I substrates.
- Maximal mitochondrial membrane potential (Delta psi) showed no significant difference, but increased during ADP-induced depolarization with succinate.
- Mitochondria from STZ-treated rats exhibited decreased susceptibility to calcium-induced MPTP opening and reduced caspase 9-like activity.
Conclusions:
- Eighteen weeks of STZ-induced hyperglycemia reduced gastrocnemius mitochondrial respiratory control and calcium-dependent MPTP opening.
- Mitochondrial effects of hyperglycemia appear to be time- and organ-specific.
Related Concept Videos
01:29Hyperglycemia
Hyperglycemia is an abnormally high blood glucose level. It is diagnosed by fasting glucose ≥126 mg/dL, 2-hour oral glucose tolerance test (or OGTT) ≥200 mg/dL, random glucose ≥200 mg/dL with symptoms, or HbA1c ≥6.5%. However, HbA1c results may be unreliable in certain conditions, such as anemia or hemoglobinopathies, and the diagnosis should be confirmed unless classic symptoms are present. Postprandial hyperglycemia is typically considered significant when glucose levels exceed 180 mg/dL two...
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.
01:22Diabetes Mellitus: Type 2 and Gestational
Type 2 diabetes, characterized by insulin resistance, arises when the insulin receptors on cells lose responsiveness to insulin, diminishing the cell's capacity to take up glucose, resulting in elevated blood glucose levels. To receive a diagnosis of Type 2 diabetes, a series of blood glucose tests are necessary to assess whether the blood glucose falls within normal parameters. If the result is out of the normal range, a patient may be diagnosed as prediabetic or diabetic, depending on the...
01:23Dipeptidyl Peptidase 4 Inhibitors
Dipeptidyl peptidase 4 (DPP-4) is a serine protease widely distributed in the body. It's involved in the inactivation of GLP-1 and GIP hormones, which are crucial for insulin regulation. DPP-4 inhibitors, such as sitagliptin (Januvia), saxagliptin (Onglyza), linagliptin (Tradjenta), alogliptin (Nesina), and vildagliptin (Galvus), help increase the proportion of active GLP-1, enhancing insulin secretion. These inhibitors work by competitively binding to DPP-4. This binding causes a significant...
01:22Complications of Diabetes Mellitus
Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia due to insulin deficiency, resistance, or both. Prolonged hyperglycemia disrupts metabolic homeostasis and leads to acute and chronic complications.Acute ComplicationsAcute complications result from sudden metabolic imbalance.Diabetic ketoacidosis (DKA) mainly appears in type 1 diabetes but may also develop in type 2 diabetes, particularly under extreme stress. It arises from severe insulin deficiency,...
01:19Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
α-glucosidase inhibitors, including acarbose (Precose), miglitol (Glyset), and voglibose (Voglib) (primarily available in Asia), are drugs that control blood sugar levels by delaying the digestion of starch and disaccharides. They achieve this by inhibiting α-glucosidase enzymes in the intestine, which slow the absorption of carbohydrates in the intestine, which in turn leads to a prolonged release of the glucoregulatory hormone GLP-1 from intestinal L-cells.
Acarbose and miglitol are typically...
Acarbose and miglitol are typically...